Logging drone with wiper plug

ABSTRACT

An autonomous logging drone tool-string including a wiper plug at a downstream end, a logging tool, and a detachable transmitter capsule, and associated methods for cementing a wellbore and logging wellbore information in a single tool-string run downhole. In an aspect, the logging drone tool-string may include a perforating gun and associated methods may include perforating a toe end of the wellbore casing and surrounding cement. In an aspect, the transmitter capsule stores wellbore information from the logging tool. The transmitter capsule may be detached, pumped to the surface, and retrieved for accessing the stored wellbore information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/957,381 filed Jan. 6, 2020. This application claimsthe benefit of U.S. Provisional Patent Application No. 63/040,393 filedJun. 17, 2020. The entire contents of each application listed above areincorporated herein by reference.

BACKGROUND OF THE DISCLOSURE

The present disclosure is generally directed to wellbore completionoperations. As shown in the cross-sectional view of FIG. 1, a typicalwellbore site 100 includes a wellbore 101 that has been drilled into ahydrocarbon formation 130 and extends from a surface 110 of the wellbore101/hydrocarbon formation 130 to an end, or toe 111, of the wellbore101. As part of preparing the wellbore 101 for perforating andcompletion operations to extract oil and/or gas from the hydrocarbonformation 130, a wellbore casing 120, as multiple segments, is insertedinto the wellbore 101. The configuration/profile of the wellbore casing120 generally matches the profile of the wellbore 101 but a diameter ofthe wellbore casing 120 is less than a diameter of the wellbore 101 soas to leave an annulus 121 of generally empty space between the wellborecasing 120 and the surrounding hydrocarbon formation 130.

A cement slurry 140 is then pumped down the wellbore casing 120 which isopen at the toe end 111 to allow the cement slurry 140 to fill the toeend 111 of the wellbore 101. The pump-down pressure forces the cementslurry 140 to then fill the annulus 121 around the wellbore casing 120,from the toe end 111 towards the surface 110, to seal the wellborecasing 120 within the wellbore 101. After a sufficient amount of cementslurry 140 has been pumped into the wellbore 101, a wiper plug (or,“cement plug”) 210 (FIG. 3) is deployed into the wellbore casing 120 toforce any remaining cement slurry 140 out of the wellbore casing 120,towards the toe end 111 and into the annulus 121, as is known.

Once the above cementing operations are complete, a wellbore tool suchas a perforating gun may be deployed into the wellbore casing 120 toperform a completion operation such as perforating the wellbore casing120, surrounding cement 140, and hydrocarbon formation 130, to recoverthe hydrocarbons. However, before performing additional wellboreoperations, a logging device (not shown) may be pumped down the wellborecasing 120 on a conveyance such as a wireline, e-line, coiled tubing ore-coil, to log the structural layout of the wellbore 101 and otherwellbore conditions by, e.g., logging and recording the position ofmagnetic markers, beacons, casing couplings, and the like. Generating aprofile of the wellbore 101 and the conditions at various locationswithin the wellbore casing 120 may allow operators to position wellboretools more precisely during various operations.

As described above, known techniques for performing the above operationsrequire multiple “runs” into the wellbore 101; i.e., each of the wiperplug, logging device, and perforating gun (or other wellbore tool) mustbe separately deployed into the wellbore 101. The logging device andperforating gun must be conveyed on a physical conveyance, andthereafter removed from the wellbore by the physical conveyance.Further, the logging device and perforating gun, for example, mayrequire a communicative electrical connection (e.g., as a component ofthe physical conveyance) to computers at the surface 110 for providinginitiating and other instructions to the devices, and sendinginformation from the logging device to the surface. These aspectsincrease the time, cost, and personnel required for wellborepreparation.

Accordingly, devices, systems, and methods for combining the aboveoperations and eliminating the need for physical connections betweenwellbore tools and the surface of the wellbore would be beneficial.

BRIEF DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

In an aspect, the disclosure relates to an autonomous logging dronetool-string. The autonomous logging drone tool string may comprise awiper plug at a downstream end, a logging tool, and a transmittercapsule in electrical communication with the logging tool. Thetransmitter capsule may be configured for detaching from the loggingdrone tool-string.

In an aspect, the disclosure relates to an autonomous logging drone thatmay comprise a wiper plug, a perforating gun, a trigger module, alogging tool, and a transmitter capsule. Each of the wiper plug, theperforating gun, the trigger module, the logging tool, and thetransmitter capsule may be connected as a tool-string, and the wiperplug may be positioned at a downstream end of the tool-string.

In an aspect, the disclosure relates to a method for cementing awellbore and logging wellbore information. The method may comprisepumping cement down a wellbore casing within the wellbore and deployinga logging drone into the wellbore casing. The logging drone may includea wiper plug at a downstream end and a logging tool positioned upstreamof the wiper plug. The logging drone may include a transmitter capsulein electrical communication with the logging tool. The method mayfurther comprise pumping the logging drone down the wellbore casing witha wellbore fluid and pushing cement out of the wellbore casing with thewiper plug. The method may further comprise collecting wellboreinformation with the logging tool and storing the wellbore informationin the transmitter capsule. The method may further comprise retrievingthe wellbore information from the transmitter capsule.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description will be rendered by reference to exemplaryembodiments that are illustrated in the accompanying figures.Understanding that these drawings depict exemplary embodiments and donot limit the scope of this disclosure, the exemplary embodiments willbe described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIG. 1 is a cross-sectional view of a typical wellbore site andwellbore;

FIG. 2 is a side view of a logging drone with wiper plug according to anexemplary embodiment;

FIG. 3 is a partial cross-sectional view of a wiper plug according to anexemplary embodiment;

FIG. 4 is a breakout view of a logging drone with wiper plug accordingto an exemplary embodiment;

FIG. 5 is a cross-sectional view of a ballistic release tool accordingto an exemplary embodiment;

FIG. 6 shows a transmitter capsule and transmitter holder, andassociated components, according to an exemplary embodiment;

FIG. 7 is a cross-sectional view of trigger module according to anexemplary embodiment;

FIG. 8 shows a trigger module switch according to an exemplaryembodiment; and

FIG. 9 shows a trigger module control unit according to an exemplaryembodiment.

Various features, aspects, and advantages of the exemplary embodimentswill become more apparent from the following detailed description, alongwith the accompanying drawings in which like numerals represent likecomponents throughout the figures and detailed description. The variousdescribed features are not necessarily drawn to scale in the drawingsbut are drawn to emphasize specific features relevant to someembodiments.

The headings used herein are for organizational purposes only and arenot meant to limit the scope of the disclosure or the claims. Tofacilitate understanding, reference numerals have been used, wherepossible, to designate like elements common to the figures.

DETAILED DESCRIPTION

Reference will now be made in detail to various exemplary embodiments.Each example is provided by way of explanation and is not meant as alimitation and does not constitute a definition of all possibleembodiments. It is understood that reference to a particular “exemplaryembodiment” of, e.g., a structure, assembly, component, configuration,method, etc. includes exemplary embodiments of, e.g., the associatedfeatures, subcomponents, method steps, etc. forming a part of the“exemplary embodiment”. For purposes of this disclosure, the phrases“device(s),” “system(s),” and “method(s)” may be used eitherindividually or in any combination referring without limitation todisclosed components, grouping, arrangements, steps, functions, orprocesses.

An exemplary embodiment of a logging drone with wiper plug 200 (“drone”)according to the disclosure is shown in FIG. 2. For purposes of thisdisclosure, a “drone” is a self-contained, autonomous or semi-autonomousvehicle for downhole delivery of one or more wellbore tools. Forexample, the exemplary drone 200 may be a tool-string which can bepumped downhole with the wellbore fluid, without conventional conveyancemethods such as a wireline, e-line, coiled tubing or e-coil, orcommunicative connections with the surface of the wellbore.

In the exemplary embodiment shown in FIG. 2, the drone 200 includes,among other things, a wiper plug 210 at a downstream end 211 of thedrone 200, a perforating gun string 220 which may include one or moreperforating guns, including shaped charges 221, connected to the wiperplug 210, for perforating the wellbore casing, cement, and/orsurrounding hydrocarbon formation, and a programmable trigger module 230connected to the perforating gun string 220 and capable of, among otherthings, initiating each of the one or more perforating guns in theperforating gun string 220 as per a programming sequence input at thesurface of the wellbore (before the drone 200 is deployed into thewellbore). It is understood that the programmable trigger module 230 mayinclude an electronic trigger circuit and power supply or otherprogrammable or otherwise control-capable component for carrying out theprogrammed operations, e.g., initiating the one or more perforating gunsaccording to the programming sequence. For purposes of this disclosure,“downstream” means further into the wellbore towards the toe of thewellbore, and “upstream” means further towards the surface of thewellbore.

Continuing with reference to FIG. 2, a logging tool 240 including,without limitation, one or more sensors to record the depth of the drone200 and log the structural layout of the wellbore is connected to thetrigger module 230 component/section of the tool-string (or, theperforating gun string 220 to the extent that the trigger module 230 maybe integrated with the perforating gun string 220 assembly). Atransmitter capsule or module 250 which can be separated from the drone200 and pumped back to surface or retrieved back to the surface by othermeans is connected to and in electrical data communication with thelogging tool 240 and associated componentry. For purposes of thisdisclosure, “electrical data communication” includes wirelesscommunication such as, without limitation, radio-frequency and Bluetoothcommunication. While the transmitter module 250 is shown as beingconnected to the upstream end 212 of the drone 200 tool-string, it iscontemplated that the transmitter module 250 may be circumferentiallydisposed about the logging tool 240, perforating gun string 220 or anyother tool or component of the drone 200.

The drone 200 may be deployed downhole after the cement slurry has beenpumped into the wellbore. The logging tool 240 component/section of thetool-string logs and records magnetic markers, beacons, casing couplingsand other properties in the cased wellbore as the drone 200 is conveyeddownhole. In an aspect, the exemplary drone 200 may be configured as alogging drone on which a logging device is the only component. Thelogging drone may be sent down the wellbore after position markers havebeen deployed/set in the wellbore or wellbore casing. The logging dronemay confirm the placement of the markers that have been set. In anaspect, the logging tool 240 of the drone 200 tool-string or a loggingtool as part of a logging drone or other drone tool-string may include awireless transmitter to transmit data directly back to a receiver at thesurface of the wellbore.

With continuing reference to FIG. 2 and the exemplary embodiment,logging data is stored in the transmitter module 250. The wiper plug 210is positioned at the downstream end 211 of the drone 200 and the drone200 is forced downhole by pumping with fluid. The downward motion of thewiper plug 210 pushes remaining cement slurry out of the open wellborecasing 120 at the toe end 111 of the wellbore and forces the cementslurry into the annulus 121 between the wellbore casing 120 andhydrocarbon formation 130. The wiper plug 210 may also separate the pumpfluid from the cement by its design, as discussed below. The cement 140in the annulus 121 is then allowed to set and thereby seal the annulus121. Once the cement 140 is set, the one or more perforating guns in thegun string 220 are initiated by the trigger module 230 via thepre-programmed imitating sequence which is set at surface prior todeployment.

After the detonation of the perforating gun(s) in the perforating gunstring 220 has been confirmed by the trigger module 230, the transmittercapsule 250 is separated from the rest of the drone 200 tool-stringeither ballistically or by other means, such as mechanical detachment,degradation of connecting materials, and the like, and is pumped back tothe surface of the wellbore so the logging data may be retrieved. Inanother technique, the drone 200 may be positively buoyant to aid in itsreturn to the surface while fluid is being pumped into the wellbore. Theperforated section(s) of the wellbore toe end 111 allow furtherpump-down operations to take place because the wellbore fluid within thewellbore casing 120 is hydraulically connected to the hydrocarbonformation 130 by the perforations created through the wellbore casing120 and dried cement 140 in the annulus 121.

With reference now to FIG. 3, an exemplary wiper plug 210 is shown. Theexemplary wiper plug 210 includes a downstream head portion 310 thatwill be furthest downstream when the drone 200 is deployed in thewellbore. A connecting portion 330 is opposite and upstream from thehead portion 310. The connecting portion 300 is configured forconnecting to a wellbore tool or drone 200 tool-string component such asa perforating gun of the perforating gun string 220 in the exemplaryembodiment shown in FIG. 2. The connection between the perforating gunstring 220 and the wiper plug 210 may be, without limitation, a threadedconnection, or in certain embodiments the wiper plug 210 may be formedintegrally (i.e., as a single piece) with, e.g., a perforating gunhousing in the perforating gun string 220. Other connections between thewiper plug 210 and the perforating gun string 220 and generally betweenthe various components of the drone 200 tool-string may be any knownconnection or technique consistent with this disclosure.

The wiper plug 210 may include, e.g., fins 320 extending radiallyoutwardly for collecting and pushing the cement slurry and separatingthe cement slurry from the wellbore fluid. The fins 320 also aid incleaning the inner surface of the wellbore casing 120 by scraping offcement slurry (and potentially other materials) that have collected onthe wellbore casing 120. Other components of the exemplary wiper plug210 shown in FIG. 3 are well known and may include, for example, athrough-bore 201 for accomondating a hydraulic or electrical connectionthrough the wiper plug 210, a box (female) connection 202 for, e.g.,accommodating cross-over handware, one or more vertical bores 203 forenabling the wiper plug 210 to be pressure balanced with the well-borepressure, a port 204 and an adapter 205 for accommodating a diaphragm orrupture unit (not shown) for allowing the cement slurry to pass throughafter the wiper plug 210 reaches a landing position.

With reference now to FIG. 4, an exemplary embodiment of a drone 200 mayinclude a ballistic release tool 260 including a transmitter holder 262in which the transmitter capsule 250 is held, and a release tool housing264 connected to each of the transmitter holder 262 and the logging tool240. The ballistic release tool 260, according to the exemplaryembodiments, detachably connects the transmitter capsule 250 to thedrone 200, as discussed further below. According to an exemplary method,the logging tool 240 transmits data to the transmitter capsule 250 andthe transmitter holder 262, including the transmitter capsule 250,detaches from the drone 200 and travels to the wellbore surface 110 (viabuoyancy, pumping, or other known consistent techniques) for retrievaland data collection. An illustrative ballistic release tool includingfunctional aspects is described in U.S. Patent Publication No.2019/0330947 published Oct. 31, 2019 and commonly owned byDynaEnergetics Europe GmbH, the contents of which are, to the extentsuch contents are not inconsistent with this disclosure, incorporatedherein by reference. The exemplary ballistic release tool 260 isconfigured for operation with an autonomous drone as discussedthroughout this disclosure. For example, the exemplary ballistic releasetool 260 does not require a wired connection to a power supply orcontrol device at the surface 110 of the wellbore 101.

The release tool housing 264 may connect to the logging tool 240 by, forexample and without limitation, a male threaded connection end 265 thatis received in a complementary female threaded connection portion (notshown) of the logging tool 240. In other embodiments, the connectionbetween the release tool housing 264 and the logging tool 240 may be byknown consistent techniques including set screws, latches or othermechanical locking, and the like. In still further embodiments, thelogging tool 240 may be formed integrally with the release tool housing264, or the logging componentry, such as, without limitation, circuitsand controllers, sensors, transmitters, and other logging componentry asknown in the art, may be housed within a portion of the release toolhousing 264 adapted to house the componentry. In still otherembodiments, the connection between the release tool housing 264 and thelogging tool 240 may be indirect, for example via an adapter. Generally,logging devices are functionally well known and the configuration of thelogging tool 240 and/or associated componentry for incorporation in theexemplary embodiments of a drone 200, as discussed throughout thisdisclosure, may take any form consistent with, e.g., making theconnections and/or housing the componentry in the drone 200.

With additional reference to FIG. 5 and FIG. 6, according to anexemplary embodiment, each of the transmitter holder 262 and the releasetool housing 264 encloses an inner chamber. The transmitter holder 262is configured to connect to the transmitter capsule 250 by, for example,a threaded connection 267 within the inner chamber. The transmittercapsule 250 may generally be configured in any manner consistent withthis disclosure, including, e.g., connecting or being secured to thetransmitter holder 262 and housing necessary componentry such as a powersource, electronic transmitter/receiver, memory, controller, and/orother componentry as well known. In other embodiments, the transmittercapsule 250 may be formed integrally with the transmitter holder 262, orthe associated componentry may be housed in the transmitter holder 262and the transmitter holder 262 may be configured to house thecomponentry.

The transmitter holder 262 and the release tool housing 264, accordingto the exemplary embodiments shown in FIG. 5 and FIG. 6, may beconnected to one another by a connecting means such as a connectingsleeve 263. According to an aspect, the connecting means may includethreaded connections 266 or other known consistent coupling mechanisms.As discussed further below, the connecting sleeve 263 may be designed tobe rigidly connected, e.g., through the threaded connection 266, to oneof the transmitter holder 262 or the release tool housing 264 andreleasably connected to the other of the transmitter holder 262 or therelease tool housing 264. Under such circumstances, release of thereleasable connection results in disconnection of the transmitter holder262 from the release tool housing 264.

In an exemplary embodiment, release by the connecting sleeve 263 may bedeliberately caused by an explosive force from a detonator 274. It iscontemplated that the detonator 274 may be a wired detonator or awireless detonator. Thus, separation of the transmitter holder 262 fromthe release tool housing 264 may be initiated by detonating thedetonator 274. According to the exemplary embodiment shown in FIG. 5, adetonator housing 270 is connected at one end to the transmitter holder262, via a threaded connection 271 within the inner chamber of thetransmitter holder 262, and extends upward into the inner chamber of therelease tool housing 264. The detonator housing 270 includes acylindrical center bore 273 primarily occupied by the detonator 274contained in a detonator sleeve 272. A bushing 275 may be screwed in orotherwise connected to the upper end of the center bore 273 and may helpmaintain the position and stability of the detonator 274 and reliableelectrical contacts thereto, as discussed further below. According to anaspect, the bushing 275 is composed of an insulating or insulativematerial.

According to the exemplary embodiment shown in FIG. 5, the detonator 274includes a detonator head 276, a detonator shell 277, an electricalcircuit board 278 and an explosive load 279. The detonator head 276 haselectrical contacts 280, 281 for contacting a line-in 282 and a line-out283. The line-in electrical contact 280 and the circuit board 278 areconfigured for receiving an ignition signal from the line-in 282. In anexemplary embodiment, the line-in 282 may be in electrical communicationwith, and transmit the ignition signal from, the logging tool 240, via aconductive pin 290 in electrical contact with, e.g., a signal contact ofa control circuit in the logging tool 240, and a conductive spring 291biasing the conductive pin 290 for the electrical contact. The loggingtool control circuit may be programmed for outputting the ignitionsignal, via the signal contact, in response to, without limitation, acompleted data collection cycle, a depth of the drone 200 within thewellbore 101, an elapsed time after deployment or passing a marker inthe wellbore, and the like. In response to receiving the ignition signalvia the line-in electrical contact 280, the circuit board 278 may,according to an aspect, send an electrical signal to a fuse head thatignites and detonates the explosive load 279 according to knowntechniques. The detonation generates an explosive force, as discussedfurther below.

The line-out 283 may be, e.g., a conductor rod electrically connected,at a first end, to the line-out electrical contact 281 of the detonatorhead 276, and, at a second end, to a terminal contact 292. To the extentthat the conductor rod 283 needs to pass through any structural element,such as the detonator housing 270, in order to connect to the line-outelectrical contact 281 and the terminal contact 292, a channel may beprovided through that structural element. According to the exemplaryembodiment shown in FIG. 5, the terminal contact 292 is provided withina complementary portion of the inner chamber of the transmitter holder262 including an insulator 293. A connector receptacle 294 is formed inthe terminal contact 292. The transmitter module 250 includes acommunication pin 295 extending from the transmitter module 250 andconfigured for being received within the connector receptacle 294 andthereby in electrical contact with the terminal contact 292. Accordingto an aspect, the conductor rod 283 may transmit data from the loggingtool 240 to the transmitter module 250, via the terminal contact 292 andcommunication pin 295. The conductor rod 283 may relay the data from theline-out electrical contact 281 of the detonator head 276. For example,when the line-in electrical contact 280 receives a signal that is notthe ignition signal, the signal is passed to the line-out electricalcontact 281 for transmission via the conductor rod 283. Thus, signalscarrying logging data may be communicated from the signal contact of thelogging tool control circuit to the transmitter module 250.

With further reference to the exemplary embodiments shown in FIG. 5 andFIG. 6, a plurality of tubing fingers 300 extend from the transmitterholder 262. According to an aspect, a space, groove or channel 302 isbetween each tubing finger 300. Each tubing finger 300 continues to forminto a tip, protrusion or flange 304 at the upper end of the transmitterholder 262. The space 302 between tubing fingers 300 allows each finger300 to deflect radially inward and outward when subjected to a radialforce, particularly to a radial force exerted on the flange 304 thereof.When fingers 300 are subjected to an outward radial force, flanges 304are adapted to be received within one or a plurality of compatiblereceiving grooves or recesses 306 in an inner wall of the release toolhousing 264. The flanges 304 and receiving groove 306 permit atightening engagement between the transmitter holder 262 and the releasetool housing 264.

According to an aspect, a latch 308 is circumferentially mounted on theexternal surface of the detonator housing 270. The latch 308 may besubstantially cylindrical. According to an exemplary embodiment, one ora plurality of shear pins 309 extend through the annular wall of latch308 and engage pin channels (not shown) in the detonator housing 270 andfunction to prevent unintentional movement of the latch 308 relative tothe detonator housing 270. For example, the shear pins 309 prevent thelatch 308 from shifting axially along the outer surface of the detonatorhousing 270. Thus, once the latch 308 is properly placed on thedetonator housing 270, the shear pins 309 will hold the latch 308 inplace relative to the detonator housing 270.

According to the exemplary embodiments shown in FIG. 5 and FIG. 6, thelatch 308 is mounted onto the external surface of the detonator housing270 and the detonator housing 270 is inserted into the inner chamber ofrelease tool housing 264. As the detonator housing 270 is insertedthrough the inner chamber of the release tool housing 264 and connectedto the transmitter holder 262, an outer surface of the latch 308 slidesunder the flanges 304 of the tubing fingers 300 and exerts a radiallyoutward force on the flanges 304 of the tubing fingers 300. When thedetonator housing 270 is fully connected with (e.g., threaded into) thetransmitter holder 262, the latch 308 is thereby lodged under theflanges 304 and causes the flanges 304 to be disposed in the receivinggrooves or recesses 306.

In addition, when the detonator housing 270 is fully connected to thetransmitter holder 262, the latch 308 lodged under the flanges 304causes undersides 310 of the flanges 304 to each engage a top surface312 of the connecting sleeve 263. Engagement of the flange undersides310 with the top surface 312 of the connecting sleeve 312 will preventthe connecting sleeve 263 from disengaging from the tool transmitterholder 262. Removal of the outward radial forces on the fingers 300 bythe latch 308 will result in the flange undersides 310 disengaging fromthe top surface 312 of the connecting sleeve 263. A certain amount ofaxial force acting to pull the transmitter holder 262 and the releasetool housing 264 away from each other when the undersides 310 of theflanges 304 are not engaged with the top surface 312 of the connectingsleeve 263 will result in disconnection of the transmitter holder 262and the release tool housing 264. In the exemplary embodiments shown inFIG. 5 and FIG. 6, the release tool housing 264 is connected to theconnecting sleeve 263 by the threaded connection 266. Thus,disengagement of the flanges 304 from the connecting sleeve 263 resultsin the transmitter holder 262 and the connecting sleeve 263 disengagingfrom the release tool housing 264.

With continued reference to FIG. 5, a central vent 315 in the lowerportion of the detonator housing 270 extends downward from the centerbore 273. One or more radial vent(s) 316 extend radially from thecentral vent 315 to the exterior of the detonator housing 270. Each ofthe radial vents 316 exits the detonator housing 270 at a vent port 318into an expansion chamber 320 bounded by an external surface of thedetonator housing 270 and an internal surface of the connecting sleeve263, and/or an internal surface of the release tool housing 264.

Upon detonation of detonator 274, rapidly expanding gases fill theradial vents 316 and the expansion chamber 320. Proper sealing of theexpansion chamber 320, e.g., by various o-rings 325, results in theexpanding gases building pressure within the expansion chamber 320. Thispressure builds as the explosive load 279 and/or another energeticmaterial in the detonator 274 continues to burn, exerting an increasingaxial force on the latch 308, in a direction away from the transmitterholder 262. The amount of energetic material, e.g., volume of theexplosive load 279, is selected such that the axial force exerted on thelatch 308 exceeds the force necessary to shear the shear pin(s) 309.Once the shear pin(s) 309 are sheared, the latch 308 is able to moveaxially away from the transmitter holder 262. This axial movement of thelatch 308 will result in the latch 308 no longer exerting an outwardradial force on the fingers 300, and the flanges 304 will disengage fromthe connecting sleeve 263 and the recesses 306. The axial force willlikewise detach the transmitter holder 262, including the transmittermodule 250, from the release tool housing 264, allowing the transmittermodule 250 to be retrieved at the surface 110 of the wellbore 101according to known techniques for, e.g., retrieving wellbore tools thathave been returned from within the wellbore.

A ballistic release tool for use with the exemplary embodiments of adrone 200 as discussed throughout this disclosure is not limited to theexemplary embodiments shown in FIG. 5 and/or FIG. 6. Other knownballistic release tools, mechanisms, techniques, etc. consistent withthis disclosure may be incorporated for ballistically detaching atransmitter capsule, according to the exemplary embodiments.

With reference now to FIG. 7, and continuing reference to FIG. 4, atrigger module 230 according to an exemplary embodiment includes,without limitation, a top housing 402 connected to a bottom housing 404.According to the exemplary embodiments shown in FIG. 4 and FIG. 7, thebottom housing 404 may include a male threading 406 for directlycoupling with, e.g., a complementary female threading (such as femalethreading 224) on a gun housing 222 of a perforating gun in theperforating gun string 220. While a single perforating gun is shown,e.g., in FIG. 2 and FIG. 4, according to the exemplary embodiments, itis understood that the perforating gun string 220 may include aplurality of perforating guns connected in series. Accordingly, it isalso understood that, as in the exemplary embodiments shown in FIG. 4and FIG. 7, the male threading 406 on the trigger module 230 connects tofemale threading on the gun housing of the furthest upstream perforatinggun, while female threading 224 on the furthest downstream perforatinggun connects to a male threading end 215 of the wiper plug 210. Invarious embodiments, a cross-over sub or other hardware (not shown) maybe positioned between and connect the furthest downstream perforatinggun 220 and the wiper plug 210. Such connection generally may take anyform and include any known consistent components and/or configurations.

In other embodiments, the trigger module 230, the perforatinggun/perforating gun string 220, and the wiper plug 210 may variouslyconnect by any known consistent techniques including, withoutlimitation, cross-over subs, latches, mechanical locking mechanisms, setscrews, and the like. In still other embodiments, two or all of thetrigger module 230, a perforating gun (i.e., furthest upstream orfurthest downstream), and the wiper plug 210 may be formed integrally.

Generally, any tools or components included in a drone 200 as describedthroughout this disclosure may be configured, connected, and/orassembled in any manner consistent with the disclosure, including, e.g.,making connections and/or housing componentry in the drone 200.

Within continuing reference to FIG. 7, the top housing 402 may bedimensionally configured for connecting with the logging tool 240. Forexample, the top housing 402 may include female threading 403 within acavity 405 of the top housing 402. The cavity 405 and female threading403 may respectively receive and connect to a male threaded projection241 on the logging tool 240. According to the exemplary embodiment, thetrigger module 230 includes a frame 410 configured to mount a circuitboard 415. The circuit board 415 may include a logic circuit 420 (FIG.9). A switch 430 supplies power to the logic circuit 420, via a firstelectrical contact 431 (FIG. 8) operably coupled (dashed line) to apower source 440 and a second electrical contact 432 operably coupled(dashed lined) to the logic circuit 420, as further shown and describedwith respect to FIG. 9. The power source 440 in the form of, withoutlimitation, a battery pack, may be mounted on a lower side of the frame410, although not shown in FIG. 7. The power source 440 may be batterysuch as a lithium ion battery or another electrical power storagedevice. The power source 440 may be mounted on the circuit board 415 orseparately mounted within the trigger module 230.

The trigger module 230 may be in electrical communication with thelogging tool 240. For example, the trigger module 230 may include one ormore signal receivers 407 for receiving electrical signals from thelogging tool 240. The logging tool control circuit (as previouslydiscussed) may output electrical signals regarding, e.g., a depth,orientation, or position of the drone 200, i.e., relative to a marker,within the wellbore 101. One or more electrical connections (not shown)such as, without limitation, cables, wires, contacts, and the like, maybe positioned within a respective channel 408 adjacent to each signalreceiver 407. In an aspect, one or more of the signal receivers 407 maybe replaced by a signal transmitter to enable two-way communicationbetween the logging tool 240 and the trigger module 230.

The signal receiver 407 (for purposes of this disclosure, “the signalreceiver 407” is used for brevity but understood to describe each of aplurality of signal receivers 407 and/or one or more transmitters,unless otherwise specified) may be operably coupled to the logic circuit420 via cables (not shown) or other suitable connection. The signalreceiver 407 may be powered via the logic circuit 420 once the switch430 is closed. Alternatively, the signal receiver 407 may be providedwith its own power supply. The signal receiver 407 may be configured torelay an electrical signal, e.g., from the logging tool 240, to thelogic circuit 420. The logic circuit 420 may be configured to output anoperation signal for, without limitation, controlling each perforatinggun in the perforating gun string 220. The operation signal may be basedon, e.g., the electrical signal from the logging tool 240 and/or aninput signal from another component, such as a sensor, timing circuit,and the like. Such components may be part of the trigger module 230 butmay generally be located anywhere from which communication with thelogic circuit 420, including wireless communication (i.e.,radio-frequency, Bluetooth, etc.), is enabled.

With reference to FIG. 8, an exemplary embodiment of the switch 430 isshown. The switch 430 may include the first electrical contact 431operably coupled to the power source 440, the second electrical contact432 operably coupled to the logic circuit 420, and a third electricalcontact 433. In an aspect, the power source 440 and the logic circuit420 may be de-coupled or open-circuited unless both the first electricalcontact 431 and the second electrical contact 432 are contacted by thethird electrical contact 433. The third electrical contact 433 may bemounted on a second circuit board 434, which may be mounted on a backingdisk 435 for mechanical support. The second circuit board 434 and thebacking disk 435 may be mounted on a piston 492 (FIG. 7) via a screw 436inserted into a hole 493 provided in an end of the piston 492. When thepiston 492 pushes the third electrical contact 433 into contact with thefirst electrical contact 431 and the second electrical contact 432,thereby closing the switch 430, power is supplied from the power source440 to the logic circuit 420.

With reference now to FIG. 9, an exemplary embodiment of a control unit450 is shown. In the exemplary embodiment, a source 480 such as thelogging tool control circuit may output an electrical signal based on athreshold condition (pressure value or corresponding depth in the well)required before powering and arming the trigger module 230, i.e., thelogic circuit 420. For example, the signal may be based on the drone 200reaching a particular depth or position within the wellbore 101. Theswitch 430 may include circuitry configured to receive and process theoutput signal and close the switch 430 in response to the thresholdcondition being satisfied, according to the output signal. Closing theswitch 430 supplies power from the power source 440 to the logic circuit420, thereby “arming” the trigger module 230.

In further aspects, the control unit 450 may include one or more of afirst environment sensor 481 operably coupled to a first microcontroller485 and a second environment sensor 482 operably coupled to a secondmicrocontroller 486. The first environment sensor 481 may be configuredto detect a first environment condition and output a first environmentsignal based on the first environment condition. The second environmentsensor 482 may be configured to detect the first environment conditionand output a second environment signal based on the first environmentcondition. The combination of the first environment sensor 481 and thesecond environment sensor 482 may allow for independent measurement andverification of the first environment condition. The first environmentcondition may be, without limitation, a temperature of the wellboreenvironment, vibrations in the wellbore environment, or a pressure ofthe wellbore environment. The first environment condition may relate toa threshold requirement for outputting an operation signal, such as adetonation command, to the perforating gun string 220, via an outputterminal 487. Additional sensors 483, 484 may be respectively connectedto the first microcontroller 485 and the second microcontroller 486, andconfigured for, e.g., confirming the threshold condition measured by thesource 480, such as the depth or position of the drone 200 as determinedby the logging tool 240. The sensors 483, 484 may also measure one ormore other conditions, according to particular applications.

With additional reference back to FIG. 7, the trigger module 230/controlunit 450 may include an output terminal 487 operably coupled to thelogic circuit 420. The furthest upstream perforating gun in theperforating gun string 220 may be operably coupled to the outputterminal 487. Accordingly, upon a satisfaction of any thresholdrequirements for triggering perforating gun(s), the operation signaloutput by the logic circuit 420 may be transmitted to the furthestupstream perforating gun in the perforating gun string 220, via theoutput terminal 487. The additional perforating guns in the perforatinggun string 220 may be operably coupled with the furthest upstreamperforating gun, via through lines and/or switches such that anyoperation signal received by the furthest upstream perforating gun maybe passed through and selectively received by any of the perforatingguns. For example, each perforating gun may have a unique detonationcommand such that sequential operation signals output from the logiccircuit 420 may respectively initiate firing of individual perforatingguns. The sequential operation signals may be based on separatethreshold conditions or may be a preprogrammed sequence.

In other embodiments of a drone 200 according to this disclosure, thedrone 200 may include other wellbore tools, such as plugs, cutters, andthe like, and the trigger circuit 230 may be used to initiate such otherwellbore tools with a corresponding operation signal output by the logiccircuit 420. The other wellbore tools may each include control circuitryconfigured to selectively initiate in response to the operation signalreceived by the wellbore tools. In the case of the perforating gunstring 220, for example, the control circuitry may be an electronicinitiation circuit as described in U.S. Pat. No. 9,915,513 issued Mar.13, 2018, which is commonly owned by DynaEnergetics Europe GmbH, thecontents of which are incorporated herein by reference, to the extentthat such contents are not inconsistent with this disclosure.

While the trigger module 230 has been described according to theexemplary embodiments as shown, e.g., in FIGS. 2, 4, and 7-9, thetrigger module 230 generally may take any form consistent with, e.g.,making the connections and/or housing associated componentry in thedrone 200. Associated componentry may include, without limitation, apower source, an electronic controller, one or more sensors and/orconnections to output signals from other components of the drone 200,and the like.

In an exemplary method of operation of an exemplary drone according tothe embodiments discussed throughout this disclosure, the method mayinclude pumping cement down a wellbore casing of a wellbore, to fill atoe portion of the wellbore and an annulus between the wellbore casingand a hydrocarbon formation surrounding the wellbore, to isolatewellbore fluids and other contents within the wellbore casing from thehydrocarbon formation. The method may further include deploying thedrone downhole, i.e., into the wellbore via the wellbore casing. Themethod may also include pushing cement within the wellbore casingdownward with a wiper plug of the drone, as the drone travels downholein the wellbore casing. The step of pushing the cement downward with thewiper plug may include pushing the cement around open areas surroundingthe wellbore casing and/or cleaning an inner surface of the wellborecasing.

Still further, the method may further include collecting, with a loggingtool of the drone, information (i.e., data) regarding the wellbore, asthe drone travels downhole. In an aspect, the method may include sendingthe data from the logging tool to a transmitter capsule of the droneand/or storing the data in the transmitter capsule. In another aspect,the method may include wirelessly transmitting the data from thetransmitter capsule to a receiver at a surface of the wellbore. Themethod may further include detaching the transmitter capsule from thedrone and returning the transmitter capsule to the surface. In anaspect, the step of detaching the transmitter capsule may includedetaching the logging tool and the transmitter capsule, e.g., for droneembodiments in which the logging tool and the transmitter capsule aredirectly connected. In another aspect, the step of detaching thetransmitter capsule may include, without limitation, degrading afrangible or disintegrable connection and/or actuating a releasablemechanical connection between the transmitter capsule and the drone, andthe like. In a further aspect, the step of detaching the drone mayinclude separating the transmitter capsule from the drone with aballistic release tool of the drone.

Further, the method may include returning the transmitter capsule to thewellbore surface. In various aspects, the step of returning thetransmitter capsule to the wellbore surface may include pumping thetransmitter capsule to the surface or providing a buoyant transmittercapsule (and/or drone) that will float to the surface. The method mayfurther include retrieving the transmitter capsule at the surface.

The method may further include perforating, with a perforating gun orstring of perforating guns of the drone, the cemented section(s) of thewellbore. In an aspect, the step of perforating may be performed inresponse to a detonation command received at each individual perforatinggun. In another aspect, perforating may provide additional surface areafor flushing the wellbore.

The exemplary method is not limited by the number, type, or order inwhich the method steps are set forth above. In various embodiments, themethod may proceed in any manner consistent with a drone according tothe exemplary embodiments discussed throughout this disclosure and/orother embodiments consistent with this disclosure. Further, the methodmay proceed in any manner required by and consistent with wellboreoperations and/or particular applications in which the drone is used.For example and without limitation, the step of detaching thetransmitter capsule may occur at any desired time based on, e.g., theamount of data desired, and/or the step of perforating the cementedsections may occur after the step of detaching the transmitter capsule.

This disclosure, in various embodiments, configurations and aspects,includes components, methods, processes, systems, and/or apparatuses asdepicted and described herein, including various embodiments,sub-combinations, and subsets thereof. This disclosure contemplates, invarious embodiments, configurations and aspects, the actual or optionaluse or inclusion of, e.g., components or processes as may be well-knownor understood in the art and consistent with this disclosure though notdepicted and/or described herein.

The phrases “at least one”, “one or more”, and “and/or” are open-endedexpressions that are both conjunctive and disjunctive in operation. Forexample, each of the expressions “at least one of A, B and C”, “at leastone of A, B, or C”, “one or more of A, B, and C”, “one or more of A, B,or C” and “A, B, and/or C” means A alone, B alone, C alone, A and Btogether, A and C together, B and C together, or A, B and C together.

In this specification and the claims that follow, reference will be madeto a number of terms that have the following meanings. The terms “a” (or“an”) and “the” refer to one or more of that entity, thereby includingplural referents unless the context clearly dictates otherwise. As such,the terms “a” (or “an”), “one or more” and “at least one” can be usedinterchangeably herein. Furthermore, references to “one embodiment”,“some embodiments”, “an embodiment” and the like are not intended to beinterpreted as excluding the existence of additional embodiments thatalso incorporate the recited features. Approximating language, as usedherein throughout the specification and claims, may be applied to modifyany quantitative representation that could permissibly vary withoutresulting in a change in the basic function to which it is related.Accordingly, a value modified by a term such as “about” is not to belimited to the precise value specified. In some instances, theapproximating language may correspond to the precision of an instrumentfor measuring the value. Terms such as “first,” “second,” “upper,”“lower” etc. are used to identify one element from another, and unlessotherwise specified are not meant to refer to a particular order ornumber of elements.

As used herein, the terms “may” and “may be” indicate a possibility ofan occurrence within a set of circumstances; a possession of a specifiedproperty, characteristic or function; and/or qualify another verb byexpressing one or more of an ability, capability, or possibilityassociated with the qualified verb. Accordingly, usage of “may” and “maybe” indicates that a modified term is apparently appropriate, capable,or suitable for an indicated capacity, function, or usage, while takinginto account that in some circumstances the modified term may sometimesnot be appropriate, capable, or suitable. For example, in somecircumstances an event or capacity can be expected, while in othercircumstances the event or capacity cannot occur—this distinction iscaptured by the terms “may” and “may be.”

As used in the claims, the word “comprises” and its grammatical variantslogically also subtend and include phrases of varying and differingextent such as for example, but not limited thereto, “consistingessentially of” and “consisting of.” Where necessary, ranges have beensupplied, and those ranges are inclusive of all sub-ranges therebetween.It is to be expected that the appended claims should cover variations inthe ranges except where this disclosure makes clear the use of aparticular range in certain embodiments.

The terms “determine”, “calculate” and “compute,” and variationsthereof, as used herein, are used interchangeably and include any typeof methodology, process, mathematical operation or technique.

This disclosure is presented for purposes of illustration anddescription. This disclosure is not limited to the form or formsdisclosed herein. In the Detailed Description of this disclosure, forexample, various features of some exemplary embodiments are groupedtogether to representatively describe those and other contemplatedembodiments, configurations, and aspects, to the extent that includingin this disclosure a description of every potential embodiment, variant,and combination of features is not feasible. Thus, the features of thedisclosed embodiments, configurations, and aspects may be combined inalternate embodiments, configurations, and aspects not expresslydiscussed above. For example, the features recited in the followingclaims lie in less than all features of a single disclosed embodiment,configuration, or aspect. Thus, the following claims are herebyincorporated into this Detailed Description, with each claim standing onits own as a separate embodiment of this disclosure.

Advances in science and technology may provide variations that are notnecessarily express in the terminology of this disclosure although theclaims would not necessarily exclude these variations.

What is claimed is:
 1. An autonomous logging drone tool-string,comprising: a wiper plug at a downstream end of the logging dronetool-string; a logging tool; and a transmitter capsule in electricalcommunication with the logging tool, wherein the transmitter capsule isconfigured for detaching from the logging drone tool-string.
 2. Theautonomous logging drone tool-string of claim 1, wherein the transmitteris configured for ballistically detaching from the logging dronetool-string.
 3. The autonomous logging drone tool-string of claim 1,wherein the transmitter capsule is configured for storing logging dataafter detaching from the logging drone tool string.
 4. The autonomouslogging drone tool-string of claim 1, further comprising a perforatinggun positioned between the wiper plug and the logging tool.
 5. Theautonomous logging drone tool-string of claim 4, further comprising atrigger module configured for outputting a detonation command to theperforating gun.
 6. The autonomous logging drone tool-string of claim 5,wherein the perforating gun is one of a plurality of perforating guns ina perforating gun string, wherein the trigger module is configured foroutputting a detonation command for each of the plurality of perforatingguns.
 7. The autonomous logging drone tool-string of claim 5, whereinthe trigger module is in electrical communication with the logging tool.8. The autonomous logging drone tool-string of claim 5, wherein thetrigger module includes a power source and a logic circuit, wherein thelogic circuit is programmed for outputting the detonation command. 9.The autonomous logging drone tool-string of claim 8, wherein the triggermodule further includes an electrical switch between the power sourceand the logic circuit, wherein the switch is operable for changing froman open state to a closed state, and the switch in the closed statesupplies power from the power source to the logic circuit.
 10. Theautonomous logging drone tool-string of claim 9, wherein the switch isoperable for changing from an open state to a closed state in responseto an electrical signal corresponding to a threshold condition, whereinthe threshold condition is one of an environment condition, a depth, aposition, and an orientation, within a wellbore.
 11. The autonomouslogging drone tool-string of claim 1, wherein the transmitter capsule isconfigured for wirelessly transmitting logging data to a receiver. 12.The autonomous logging drone tool-string of claim 11, wherein thereceiver is positioned at a surface of a wellbore.
 13. An autonomouslogging drone, comprising: a wiper plug; a perforating gun; a triggermodule; a logging tool; and a transmitter capsule, wherein each of thewiper plug, the perforating gun, the trigger module, the logging tool,and the transmitter capsule are connected as a tool-string, and thewiper plug is positioned at a downstream end of the tool-string.
 14. Theautonomous logging drone of claim 13, wherein the logging tool and thetransmitter capsule are integrally formed.
 15. The autonomous loggingdrone of claim 13, wherein the transmitter capsule is configured fordetaching from the tool string.
 16. The autonomous logging drone ofclaim 13, wherein the transmitter capsule is positioned at an upstreamend of the tool-string.
 17. The autonomous logging drone of claim 13,further comprising a ballistic release tool connected as a part of thetool-string, wherein the ballistic release tool is connected to thetransmitter capsule and configured for detaching the transmitter capsulefrom the tool-string.
 18. A method for cementing a wellbore and loggingwellbore information, comprising: pumping cement down a wellbore casingwithin the wellbore; deploying a logging drone into the wellbore casing,wherein the logging drone includes a wiper plug at a downstream end, alogging tool positioned upstream of the wiper plug, and a transmittercapsule, wherein the transmitter capsule is in electrical communicationwith the logging tool; pumping the logging drone down the wellborecasing with a wellbore fluid; pushing cement out of the wellbore casingwith the wiper plug and collecting wellbore information with the loggingtool; storing the wellbore information in the transmitter capsule; andretrieving the wellbore information from the transmitter capsule. 19.The method of claim 18, further comprising detaching the transmittercapsule from the logging drone.
 20. The method of claim 19, furthercomprising pumping the transmitter capsule to a surface of the wellbore;and retrieving the transmitter capsule at the surface of the wellbore.